This invention relates to a method and an apparatus for sticking a continuous belt-shaped member onto a circumference of a forming drum, while cutting the continuous belt-shaped member.
The assignee of the application had proposed a method of sticking a belt-shaped member onto a forming drum with high accuracy in a reliable manner as shown in FIGS. 1a and 1b. With this method, as shown in FIG. 1a after a leading end 2 of a continuous belt-shaped member 1 has been grasped on both sides by lower pawls 6 inserted in grooves 4 of a receiving member 3 and an upper pawl 7 of a grasping unit 5, the grasping unit 5 is moved together with the belt-shaped member 1 toward a forming drum 8 to press the leading end 2 of the belt-shaped member 1 against the forming drum 8.
The belt-shaped member 1 is supplied onto the forming drum 8 being rotated to stick the belt-shaped member 1 on a substantial part of a circumference of the forming drum 8. The belt-shaped member 1 is then grasped at a position immediately before a cutting position 9 or spaced from a leading end a distance substantially equal to a circumferential length of the forming drum 8 by the lower pawls 6 inserted in grooves 10 and an upper pawl 7 of a grasping unit 5 as shown in FIG. 1b. On the other hand, the belt-shaped member 1 is pressed and positionally fixed against the receiving member 3 at a position immediately behind the cutting position 9 by a plurality of urging blocks 11 spaced from each other in width directions of the belt-shaped member 1.
A cutter 13 is caused to approach an anvil 12 of the receiving member 3 in contact with the belt-shaped member 1 at the cutting position 9, so that the belt-shaped member 1 is cut at the cutting position by the anvil 12 and the cutter 13. As a result, the portion grasped by the grasping unit 5 becomes a trailing end 14 of the belt-shaped member 1, while the portion positionally fixed by the urging blocks 11 becomes a leading end 2 of the belt-shaped member 1.
The grasping unit 5 and the belt-shaped member 1 ar moved toward the forming drum 8 being rotated to stick the remaining belt-shaped member 1 around the forming drum 8. As a result, the belt-shaped member 1 of a length substantially corresponding to one circumferential length of the forming drum is stuck onto the circumference of the forming drum 8. The cutter 13 is then moved away from the belt-shaped member 1, while the urging blocks 11 are moved away from the belt-shaped member 1 to release it from the positional fixation. The grasping unit 5 is then moved toward the receiving member 3 so that after the lower pawls 6 of the grasping unit 5 have been inserted into the grooves 4 of the receiving member 5, the leading end 2 of the belt-shaped member 1 is grasped by the upper and lower pawls 7 and 6.
With this method, there is no problem when a cross-section of the belt-shaped member is rectangular. However, in the case of a belt-shaped member having a cross-section whose thickness progressively increases toward a center in its width direction, only the center is securely urged and restrained by the urging blocks 11. As a result, both side edges of the belt-shaped member are locally contractively deformed.
Moreover, as side edges of the leading end 2 are only in contact with inner edges of the urging blocks 11, line-shaped scores often appear in a surface of the leading end 2 of the belt-shaped member. In this method, furthermore, since the urging position and the grasping position for the belt-shaped member are unavoidably coincident with each other, the urging blocks 11 are once moved away from the leading end 2 of the belt-shaped member 1 and thereafter the leading end 2 is grasped by the grasping unit 5. As a result, the restraining of the leading end 2 is lost for a short time so that the leading end 2 moves on the receiving member 3 or contractively deforms.